I have a 408 in my '74 Malibu. They are a strong engine, to say the least. A good (read strong) drive train is needed behind them, if they have performance mods. I have a Holley 750 vacuum-secondary 3310 on mine. Some tuning & mods to the carb really improved how it runs too. Had this engine in my '77 Elco for years, and I rebuilt it again and used it in the Malibu, since I elected to go with a Caddy engine in the current Elco project.